1. Field of the Invention
The present invention generally relates to color measuring devices and more specifically to systems, methods, computer-readable media, and other devices associated with measuring of color of a sample under test using a spectrophotometer or other color measuring device.
2. Description of the Related Art
A specular (mirror-path, or gloss) component of light reflecting from a material sample is often different in color from the body-reflection (perhaps matte) component. For example, in dielectric materials, the specularly-reflected light has the same relative spectrum as that of the incident illumination. Characterizing the color of a sample through a spectrophotometer (for example, an instrument based on an integrating sphere) can be designed to separate the specular from the matte component of reflection. That task is not difficult for smooth samples: Standard practice with integrating spheres simply uses a closable port that excludes or includes the light within a small incidence angle of the mirror path to the exit port of the device (the port through which the reflected light is recorded by the spectrophotometer). However, for rough samples (and particularly for textiles) such practice does not truly separate out the specular component: The specular reflection arises from elsewhere on the sphere than the specular port. Characterizing the geometry of the specular component of reflection through means other than the simple opening or closing of a hole in the integrating sphere may be useful.
A user may wish to measure the reflectance properties of a sample of material in an industrial “batch” and compare those properties with a standard sample. The “batch” may incorporate the material in a pattern (e.g., a textile pattern), whereas the standard is ensured to be calorimetrically uniform over its entire surface. A spectrophotometer can give accurate reflectance values for a sample that is spatially uniform (such as a calibrating tile). However, it is difficult to measure the reflectance spectrum of a part of a patterned material. The sample port of the spectrophotometer must be sized and shaped specifically for the part of the material specimen that is to be measured. Such adaptation may produce its own artifacts of measurement (e.g., depth of the mask next to the small area reduces the illumination to that area).
An integrating-sphere spectrophotometer can have several automatic mechanisms that determine the aperture of the sample port, whether the sample port door is open or closed, and the position of the sample. All these mechanisms are quite expensive in current implementations. Also, the spectrophotometer by itself does not allow viewing and adjustment of the sample once the sample is readied for measurement.